Add ReScript support (#5072)

This adds support for both rescript format and rescript-language-server.

Closes https://github.com/dense-analysis/ale/issues/3335

autoload/ale/fix/registry.vim

@@ -672,6 +672,11 @@ let s:default_registry = {
 \       'suggested_filetypes': ['racket'],
 \       'description': 'Fix Racket files with raco fmt.',
 \   },
+\   'rescript_format': {
+\       'function': 'ale#fixers#rescript_format#Fix',
+\       'suggested_filetypes': ['rescript'],
+\       'description': 'Official formatter for ReScript.',
+\   },
 \   'ruff': {
 \       'function': 'ale#fixers#ruff#Fix',
 \       'suggested_filetypes': ['python'],

autoload/ale/fixers/rescript_format.vim

@@ -0,0 +1,33 @@
+" Author: John Jackson <john@johnridesa.bike>
+" Description: Fix ReScript files with the ReScript formatter.
+
+call ale#Set('rescript_format_executable', 'rescript')
+call ale#Set(
+\   'rescript_format_use_global',
+\   get(g:, 'ale_use_global_executables', v:false)
+\ )
+
+function! s:GetExecutable(buffer) abort
+    return ale#path#FindExecutable(a:buffer, 'rescript_format', [
+    \   'node_modules/.bin/rescript',
+    \])
+endfunction
+
+function! s:FixWithVersion(buffer, version) abort
+    let l:exe = ale#Escape(s:GetExecutable(a:buffer))
+    let l:stdin = ale#semver#GTE(a:version, [12, 0, 0]) ? ' --stdin' : ' -stdin'
+    let l:ext = fnamemodify(bufname(a:buffer), ':e') is? 'resi'
+    \   ? ' .resi'
+    \   : ' .res'
+
+    return {'command': l:exe . ' format' . l:stdin . l:ext}
+endfunction
+
+function! ale#fixers#rescript_format#Fix(buffer) abort
+    return ale#semver#RunWithVersionCheck(
+    \   a:buffer,
+    \   s:GetExecutable(a:buffer),
+    \   '%e --version',
+    \   function('s:FixWithVersion'),
+    \)
+endfunction